knock on wood
原文解釋: express a wish that something will or will not occur
1. I think I am well at last—knock on wood.
2. I knock on wood when I wish something were true.
3. This last round of treatment should have cured her, knock on wood.
4. a. I heard there was a car accident in your neighborhood.
b. I drive by that road today so I'm knocking on wood.
5. a. I have a bad feeling about the test I took today, I might have failed it!
b. Don't say that, knock on wood!